Circuit for detecting remaining battery capacity
First Claim
1. A circuit for detecting remaining battery capacity, comprising:
- a current detection unit detecting a charge and discharge current of a battery;
a remaining capacity measurement unit including a central processing unit (CPU), the remaining capacity measurement unit measuring remaining capacity of the battery by integrating the charge and discharge current at first time intervals and at second time intervals shorter than the first time intervals, and the CPU performing a digital filter process and a remaining capacity measurement process;
an interrupt signal generation unit generating an interrupt signal to the CPU of the remaining capacity measurement unit when the charge and discharge current exceeds a reference value and instructing the remaining capacity measurement unit to measure remaining capacity of the battery, the interrupt signal allowing the CPU to enter an awake status from a sleep status;
a voltage detection unit connected to the battery and providing a voltage detection signal;
a temperature detection unit connected to the battery and providing a temperature detection signal;
a current detection unit connected to the battery and providing a current detection signal;
a sigma-delta modulator; and
a multiplexer which selects a selected detection signal from one of the voltage detection signal, the temperature detection signal, and the current detection signal, and provides the selected detection signal to the sigma-delta modulator, wherein the selection is performed based on a control signal from the CPU;
wherein the CPU judges, following the measurement of remaining capacity, whether the charge and discharge current exceeds a predetermined value, and if the charge and discharge current is not more than the predetermined value and maintained for a predetermined time, the CPU sets the time intervals for measuring the remaining capacity of the battery to the first time intervals and if the charge and discharge current exceeds the predetermined value, the CPU sets the time intervals to the second time intervals.
1 Assignment
0 Petitions
Accused Products
Abstract
A disclosed circuit for detecting remaining battery capacity includes: a current detection unit detecting a charge and discharge current of a battery; a remaining capacity measurement unit measuring remaining capacity of the battery by integrating the charge and discharge current at first time intervals when the charge and discharge current detected in the current detection unit is not more than a predetermined value and at second time intervals shorter than the first time intervals when the charge and discharge current exceeds the predetermined value; and an interrupt signal generation unit generating an interrupt signal when the charge and discharge current exceeds a reference value and instructing the remaining capacity measurement unit to measure remaining capacity of the battery.
-
Citations
9 Claims
-
1. A circuit for detecting remaining battery capacity, comprising:
-
a current detection unit detecting a charge and discharge current of a battery; a remaining capacity measurement unit including a central processing unit (CPU), the remaining capacity measurement unit measuring remaining capacity of the battery by integrating the charge and discharge current at first time intervals and at second time intervals shorter than the first time intervals, and the CPU performing a digital filter process and a remaining capacity measurement process; an interrupt signal generation unit generating an interrupt signal to the CPU of the remaining capacity measurement unit when the charge and discharge current exceeds a reference value and instructing the remaining capacity measurement unit to measure remaining capacity of the battery, the interrupt signal allowing the CPU to enter an awake status from a sleep status; a voltage detection unit connected to the battery and providing a voltage detection signal; a temperature detection unit connected to the battery and providing a temperature detection signal; a current detection unit connected to the battery and providing a current detection signal; a sigma-delta modulator; and a multiplexer which selects a selected detection signal from one of the voltage detection signal, the temperature detection signal, and the current detection signal, and provides the selected detection signal to the sigma-delta modulator, wherein the selection is performed based on a control signal from the CPU; wherein the CPU judges, following the measurement of remaining capacity, whether the charge and discharge current exceeds a predetermined value, and if the charge and discharge current is not more than the predetermined value and maintained for a predetermined time, the CPU sets the time intervals for measuring the remaining capacity of the battery to the first time intervals and if the charge and discharge current exceeds the predetermined value, the CPU sets the time intervals to the second time intervals. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. A method for detecting remaining battery capacity, comprising:
-
detecting a charge and discharge current of a battery; measuring remaining capacity of the battery by integrating the charge and discharge current at first time intervals and at second time intervals shorter than the first time intervals, and performing a digital filter process and a remaining capacity measurement process; generating an interrupt signal to a CPU of the remaining capacity measurement unit when the charge and discharge current exceeds a reference value and instructing the remaining capacity measurement unit to measure remaining capacity of the battery, the interrupt signal allowing the CPU to enter an awake status from a sleep status; judging, following the measurement of remaining capacity, whether the charge and discharge current exceeds a predetermined value; after generating an interrupt signal, controlling a multiplexer to sequentially select, in any order, a voltage detection signal, temperature detection signal, and current detection signal; converting the voltage detection signal, temperature detection signal, and current detection signal, into pulse density multiplexed (PDM) signals via sigma-delta modulation; and digitizing the PDM signals via a digital filter process; wherein, if the charge and discharge current is not more than the predetermined value and maintained for a predetermined time, the CPU sets the time intervals for measuring the remaining capacity of the battery to the first time intervals and if the charge and discharge current exceeds the predetermined value, the CPU sets the time intervals to the second time intervals. - View Dependent Claims (8, 9)
-
Specification